Shock absorber



'- Nov. 25, 1930. F. R. REIFSNIYDER 1,782,631

SHOCK ABSORBER Filed NOV. 6. 1928 55 56 INVENTOR.

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A TTORNEYQ- Patented Nov. 25, 1930 V v x ZUN'ITEDSTATES PATENT- pm,;

C reverse direction.

1 eerber shewin'gitsboxiheetieh to sprin gs ancl 12. The extreme enclofthe Stem IZ isbifur FRE -Enrol: RrItEIFSNYDER, 0 amm rErrnsYLvAmA 1fencer; ABSORBE f lApbl icatieh hledifibvember 6,1928, Serial No.3117,565.

lhis'inveutionj relates to she'ck ab serbers, tube 10,'into whichtelescopes an exteri orly andinereparticularlyt0 the provision ofdescrew-threaded valve rocl ll extending longivi ees Of this characterespecially adapted for tudirially Within anLeXteriOrly-Serew-threadf useonauteulobiles 0ieimilar vehicles/g "e clfs'terhlflfthe rod 11terhfihating infa ta- 5 The primary object'bf theinventiou is the pjeredend 13; 0peratihg asfa valve adaptetl to provision of aehock-absorheru'tilf z hrgifree open andtlqseia porgt l lin the end of the air as thecushioningmedium;in eombinatien stem 12 "IlifiliW of jthe'feregeihg, itis 0b 1 "Withcertain mechahial inetrumentalities so viqus that amovement bfthe pluugerfl,

connected ,to a relatively-f movable .support towards the endl2j0f thecasingl, will cont. 1 10 and to afrelativel'yfixed support; that, underpress airihthe chamber 4 antl c'ausef pressure mevement of theformer,the air may be autoto b e eom muhi'eated to the valve Qtenclipgtolnatically compregse'd with i tlrebedy pfthe force itfrdm its seat, suchmevenielitbf the ehbck abeqrber; land automatically expressetl valvehevvever alsbterrdihgto move the end therefrom by movement ofsaicl'suppdrt ina 13 of the rod llftowards thepert-14L e h p I M 1Coneehtrieally ,seeuretltothe reartfaee of Other Objects ofthe inventionv'v'lllbe made the pluhgerfi, and preferably integral thereappareiit inthe fllowing speeificatienswhen with, isla supplemental cempreesionchamber, read fee nectiolijwith the accompanying hereinafter call'ecl abarrel 15, Armetal plate clravvihgs formin a part thereof. 16 shrroundstherear enclef thevbarrel, hav Insaicldra vvings ing its flanges 17Secured. tofiangeslgforrrled v Fig. 1 i's'a vertical section taken"leug'ituc li oh the barrel, by nieah's' of bo1t sl9,said platethreugh ashoek-abser ber,eihbedying 16. being provided with afce trally-lqeated,niyinventioh; j screvv.-tl1reacled aperture adapted. td fopera-r Fig, 2is a side? elevatien ofthej sho ek ab tively'receivethecrew threaclsonthe stem axle and chassis 012' an automebile; and,

eateclat 20, t0'reeeiveat0'01'adaptedtefore- 3 is an end View of theshoek' absorb'er, rotate the stem; whereby, through the partlyin Sectionon th'e li e Fig. 1.. eof-eperatirlg screw threads; t forcefit for fNow.referring specifically t0 the clrawiug'e; Wardly jor rearvvarclly'Withinv the barrel 15.

in which like i'eferehee iuuheralsi"indicate as clearly illustratetlirirFigsijlaud 3h0wever, B0 like parts throughout the sever'alviews, laterally-extending "lug-s :21" arepr'ovi'decl 011 thecylindrieally-formed casingjef a shock theslmface of the rod11,ffitti11g' into sletsiu absorber embedyingmj iiweutierh said (5215-the stem 12, sothatany rbtatio pfthe stem 111;; having a .elesecleud 2,anclprevidecllwith 12 will rotate,therrodandteince the latterie aplunger 3 longitudinally reciprocate in operative serewfthreadecl"epgagemehtlfi therein thereby fermihg a eeinpression Withthe tube10, eau se threcl tqniove l011gi chamber inthe front end of theeasing 1. 'tuclinally pf Said ub thereby retaining th "lhe'plungerfiisforn'redltvith a 'eehtrallyn0rnial distai1ee betweeljflthejend {13oftl'le'.

4 positioned, hollow hub portiehfi, permitting red the portj14gFurtherlrtere lugs the passageofiair outlet the ehainber 1 a are alsdprevided he face Qftllfi euppecl leather Washer cliek 'Z-beai'lng againstfi'Qlifi end ofthe bar 15, fitting s19 the frontiace fthe \vasher and aspring the periphery ofthe valveQflvhereby te pre ring 8, seated in aperipheral: groove on the ven t rotat ioh of said valve Wheh the hub 5,servi1'1g to retain the disk 7audvthe is rotated as described,

Washer 6, in correct position. I Near the frent end oftheg 12, WithinThe rear end. of the elongated hub 5 serves the barrel 1 5, isffcarr eda peripheral flange as a seat for a valve 9 adapted to control the 235and aicuppedleather waeher5241s passage ofair through the aperture insaid held against the {flange ma ger-e 5L hub. Thevalve 955 providedWit-ha rearmetal disk 24',vwhiehgbears against salgl wardlyextending,internally screw-threaded washer, andtvhichf*is mantafeta-Watt positionby means of a spring ring pressing against said disk and seated in agroove on the periphery of the end of the stem 12.

The purpose of the structure just described is to permit a variation ofthe internal cubical content of the barrel 15. It will of course beunderstood that as the air pressure increases in cylinder 4, it willcoincidently, when the tension is in excess of valve seating spring 26',open valve 9 and close valve 13, barrel 15 receiving, relative movementof plunger 3, a varying portion of-the compressed air from cylinder 4.Illustrative of the function of the correlated automatically adjustablevalves 9 and 13, let it be presumed that plunger 3 has been suddenlyadvanced to and maintained at a certain point. The increased airpressure in cylinder 4 will open and close respectively the correlatedautomatically adjustable valves 9 and 13, permitting of equalization ofair pressure within the cylinder 4 and barrel 15. The correlatedautomatically adjustable valves 9 and. 13 will then respectively closeand open, due to tension of spring 26, exhausting part of the compressedair from barrel 15. This oscillation of the correlated automaticallyadjustable valves 9 and 13 would eventually reduce the tension in boththe cylinder 4 and barrel 15 to atmospheric pressure with valve 9closed. In practice, however, the aforesaid presumption does notprevail. WVhen shock orrebound has been overcome, the vehicle springwill move to its normal position, which through the coacting mechanismshown, carries plunger 3 therewith reducing the tension in cylinder 4which would fall below zero if not relieved by the valves 30.

Surrounding the tube 10, and rod 11, and bearing against the rear faceof the valve 9, and the washer 24, is a light coiled spring 26, tendingatall times to retain the said valve in closed position.

Mounted at spaced intervals upon plunger 3, either integral therewith orsecured thereto is a plurality of vacuum relief ports 27 having formedon its forward end a valve seat for valve 30, each of the plurality ofvalves 30 having thereon a stem 28, projecting rearwardly andlongitudinally slidable through a fixed guide within vacuum relief ports27, 29 is a spring seat washer or disk secured to valve stem 28 bycotter pin shown. A coiled spring 31 surrounds each vacuum relief port27 and, seated under the disk 29. its tension will maintain valve 30 ina closed relation to its seat formed on the forward end of vacuum reliefport 27.

Following a shock rebound plunger 3 having thereby been advanced towardthe forward end of compression chamber 4, the concomitant rearwardmovement of plunger 3 Will obviously tend to cause a vacuum within thecompression chamber 4, so that, when the air tension within cylinder 4falls below atmospheric pressure or tension, then will atmosphericpressure or tension open or lift valve 30 from its seat formed on theforward end of vacuum relief port 27, air, under atmospheric pressure ortension, entering to relieve the vacuum within cylinder 4, which is thuscharged with atmospheric air for subsequent compression on the forwardstroke of the plunger 3.

The shock absorber is provided with lugs 32 adapted to be secured to arelatively fixed resistance such as a vehicle chassis, and with means,to be now described, for connecting the plunger 3 to a relativelymovable resistance, such as the running gear of an automobile or othervehicle. In Fig. 2 the nu meral 33 represents a vehicle axle, and 34,one of the vehicle springs. A clip member 35 surrounds the spring 34,and carries a clevis 36 to which is secured a connecting, rod 37. Non-rotatably connected to a shaft 39X which is rotatably mounted in lugscarried by the shock absorber casing 1, is an arm X also pivoted to theupper end of the rod 37. Arms 39 are also non-rotatably connected toshaft 39X and have synchrm'mm movement with arm X, shaft 39X beingrotatably mounted in lugs 38. A verticallyextending drag link 40 ispivoted to said arm 39 at 41, said link being provided with a T head 42,one branch of which is connected at 41 to a link 43, pivotally mountedat 44 to the shock absorber casing 1, the other branch of the T head 42being pivotally connected at 45, to a link 46 extending in parallelismwith the link 43. The rear end of the link 46 is equipped with apulleyshaped anti-friction roller 47, mounted on a track formed by theedges of a slot 48 cut through and extending longitudinally of the shockabsorber casing 1, said roller being journa-led on a trunnion 49 securedto and extending laterally of the plunger 3, through said slot 48.

As shown clearly in Fig. 3, the connections referred to are provided onboth sides of the casing 1, but, since they are identical inconstruction and operation, a description of those on one side willsuffice.

Fron'i the foregoing the operation of the shock absorber should beclear. In the embodiment of the invention here illustrated as applied toan automobile, when the vehicle wheel descends into a concavity in thehighway. the rod 37 is pulled downwardly, resulting in a downwardmovement of the outer end of the arm X pivotally connected thereto. Suchmovement causes the arm Xto carry arm 39 with it, through shaft 39X, towhich they are fixedly keyed or otherwise secured, coincidently causingpoint 41 of the drag link 40 to describe an are. curved downwardly andto the left, resulting in a downward moveretu rn 1,7saes 1 nient oi the:pivot point 45, such movement necessarily being-in an arc/ of a circlehowever and around the pivotal points ll and A l, Wldll the result thatthe p1vot 45 must move downwardly and to the left and pull turningtonormali position on the highway,

would reversely operate thelinlrage just described. and draw the plungerrearvvardly 1n the casing 1, operating toincrease the capacity up toitsinaximum as a limit of the chamber l and tending tovform a vacuumtherein,

dependent upon the extent of movement of theplunger i As the air Withinthe compression chamber l becomes compressed to a certain extent underthe forward movement of the plunger,

()IillBllQ i ELlVS 9 exposed to said compression 2h ipressurecomniunicated to the face through the port 5, and tends to unseat saidvalve against the action of the spring 26.

Vhen the valve 9 is unseatedhovvever it moves rearwardly in the barrel15 and causes the valve 13 to close, more or less of the air thuscompressed passes into and is retained Within the barrel 15 and ifplunger 3 were stopped and maintained in this advanced positionWithinthe barrel, the compressed air in both barrel 15 and chamber 4;would, by coincident oscillations otv'alves 13 and%), gradually beezrhaustedto atmosphericpressure but, in practice, plunger 8 Will neverbe so n'laintained in advanced position Within chamber but will quicklyreturn to its normal structural position, valve. 13 through port 14exhausting barrel 1?) to atmospheric pressureand any vacuum in chamber lWlll be relieved by the plurality of air valves 30.

As the plunger 3 is projected forwardly into the chandler l', under veryviolent descent of the'vehicle "wheels, the compression in s id chanlbcrbecomes very high; and rcsuit in an innnediate openinp' of the valve l),forcing it rearwardly to an. estent sntlicient to cause the valve 13 toclo e the port 14, the shock being); absorbed her-rover in the hirer: dcompressin g;- movement of the plunger 3, as will be understood..luuneciatelyupon the movement oil the vehicle tmvards level groundhowever, a rearward movement of the plunger Will be initiatec, reducingthe pressure in chamber 4., and, since the pressure in the barrel 15 atthis time is substantially the same as in the chamber 4, the balancingforces will cause the valve 9 to move towards its seat and re-open theport 14, whereupon the pressure in the chamber a and. the barrel 15 Willbe dissipated, as hereinbetore explained.

traveli wheels 1 1 Under certain trafiic conditions, such as a overnotoriously bad roads, or with vehicles of great Weight, it isdesirablclto regulate the cubical content oilf the barrel 15, so that a:higher compression may be reached in the chan'iber 4-, under ,izivenmovement of the plunger 3. In such adjustment asuitable .tool may beapplied in a. slotQO, on the end of the stem 12,110 rotate the tter andad. Vance the Washer .2 towards evalve 9,.the rod llbcing simultaneouslyturned by the luo's 21, and-similarly enteringthe tube 10, to

inhure the maintenance of the. required distance between the valve 13and port 14., By properly adjusting the position of the Will-lib er Q la pressure of 300 lbs. per square inch may belniilt up in the chamber l,in an embodiment ofthe invention ashereillus trated.

In view or" the foregoing it will be observed that l have providedashock absorber adapted to cushion. the shock to the relat vely fixedres fence during all; changes in. position of the ativel'v movableresistance. Modlhcatioflns of: the structure herein disclosed may besuggested to those skilled in the art, but

in invention covers all embodiments falling;

fairly within the scope ofithe appended claims. v I claim 1. A shockabso-rbercomprising.a cylinder adapted for connection to a relativelyfixed support, a plungerslidable Within said cyl inder and provided Witha port adapted to permit the passage of air therethrough, a barrelcarried by the rearface of the plunger and providedwith an exhaust portinits rear portion a valve reciprocably mounted in said barrel andadapted for movement to open or close the port in said plunger, meanscarried the valve adapted, under the reciproca tions of the latter, toopen or close said exhaust po-rt, and means for operativelyconnectingsaid plunger to a relativelym'ovable a i a in) support.

2. A shock absorber comprising a cyliruler adapted for connection to arelatively fixed support, a plunger slidable Within said cylinder andprovided with aport adapted. topen out the passage of air therethrough,a barrel carried by the rear face of the plunger and provided With anexhaust. port in its rear portion, a valve reciprocably mounted in saidbarrel and adapted for movenie ,tto open or close the port in saidplunger, a stem car-- ried by the valveand adapted, under thereciprocations of the latter, to open or close said exhaust port, andmeans for o-peratively connecting said plunger to a relativelymovable'support;

35A shock absorber comprising a cylinder adapted for connection to arelatively fixed support, a plungerslidable Within said cylinder andprovided with a port adapted to permit the passage of air therethrough,a barico rel mounted on the rear face of said plunger, and having itsfront end enclosing said port, said barrel being provided with anexhaust port at its rear end, a valve structure reciprocably mounted insaid barrel and provided with means adapted to control the passage ofair through both said ports, and means operatively connecting saidplunger to a relative- 1y movable support.

4. A shock absorber comprising a'cylinder adapted to be secured to arelatively fixed support, a plunger slidable within said cylinder, andprovided with a port adapted to permit the passage of air, a barrelcarried by the rear face of the plunger and, at one end, incommunication with said cylinder through said port, said barrel carryingan exhaust port in its other end, means in said barrel, responsive tovarying air pressure, adapted for movement to control the passage of airthrough said ports, and means operatively connecting said plunger to arelatively movable support.

5. A shock absorber comprising a cylinder adapted to be secured to arelatively fixed support, a plunger slidable within said cylinder andprovided with a port adapted to permit the passage of air, a barrelcarried by the rear face of the plunger and, at one end, incommunication with said cylinder through said port, said barrel carryingan exhaust port in its other end, a valve reciprocably mounted in saidbarrel and adapted, under varying air pressure in the cylinder and barrel, for movement to control the passage of air through the port in saidplunger, a stem carried by the valve and adapted to open and close saidexhaust port, and means operatively connecting said plunger to arelatively movable support.

6. A shock absorber comprising a cylinder adapted for connection to arelatively fixed support, a plunger slidable within said cylinder andprovided with a port adapted to permit the passage of air therethrough,a barrel carried by the rear face of said plunger and in communicationwith said port at its front end and having an exhaust port at its rearend, means in said barrel, actuated by varying air pressures, adapted tocontrol the passage of air through said ports, a plurality of air valvesextending through said plunger and adapted, under air pressures appliedto the rear of the plunger, for movement to permit the passage of airthrough the latter, and means operatively connecting said plunger to arelatively movable support.

7. A shock absorber comprising a cylindcr adapted for connection to arelatively fixed support, a plunger slidable Within said cylinder andprovided with a port adapted to permit the passage of air therethrough abarrel carried by the rear face of said plunger and in communicationwith said port at its front end and having an exhaust port at its rearend, means in said barrel, actuated by varying air pressures, adapted tocontrol the passage of air through said ports, a plurality of air valvesextending through said plunger and adapted, under air pressures appliedto the rear of the plunger, for movement to permit the passage of airthrough the latter, resilient means normally retaining said air valvesin closed position, and means operatively connecting said plunger to arelatively movable support.

8. A shock absorber comprising a cylinder adapted for connection to arelatively fixed support, a. plunger slidable within said cylinder andprovided with a port adapted to permit the passage of air therethrough,a barrel carried by the rear face of said plunger and in communicationwith said cylinder through said port, said barrel being also providedwith an exhaust port at its rear end, valve mechanism in said barreladapted to control the passage of air through both said ports, means forvarying an internal dimension of said barrel, and means for connecting,said plunger to a relatively movable support.

9. A shock absorber comprising a cylinder adapted for connection to arelatively fixed support, a plunger slidable within said cylinder andprovided with a port adapted to permit the passage of air therethrough,a barrel carried by the rear face of said plunger and in communicationwith said cylinder through said port, said barrel being also providedwith an exhaust port at its rear end, valve mechanism in sald barreladapted to control the passage of air through both said ports, means forvarying an internal dimension of said barrel, said means comprising amovable end closure, means for moving said closure relatively to thebody of said barrel, and means for connecting said plunger to arelatively movable support.

10. A shock absorber comprising a cylinder having a compression chamber,a plunger adapted for reciprocation within said chamber and carrying asecond compression chamber on its rear face, both chambers being incommunication through a port in said plunger, a restricted exhaust portin said second chamber, means controlling the passage of air throughboth ports, and means for connecting said cylinder to a relativelyfixed, support and for connecting the plunger to a relatively movablesupport.

in testimony whereof I affix my signature.

FREDERICK R. REIFSNYDER.

